1. If necessary to keep the tenderloin in a compact piece, tie meat at several intervals with cotton string.
2. Melt butter in an ovenproof 10- to 12-inch nonstick frying pan over high heat. Add pork tenderloin and turn as needed to brown well on all sides, 5 to 6 minutes total.
3. Add apricot chutney and 1/3 cup water to pan and stir to incorporate meat drippings. Baste tenderloin with some of the sauce, and then put it in a 450° oven.
4. Roast pork, basting often with sauce, until meat is 150° to 155° in center of thickest part, 12 to 14 minutes. If sauce starts to scorch, stir in water, 2 tablespoons at a time.
5. Transfer the tenderloin to a platter. Pour the apricot chutney sauce over pork, or serve the sauce in a small bowl and add to taste. Slice tenderloin and season to taste with salt and pepper.
Notes: Serve with a curry-seasoned risotto or pilaf and a nippy salad of watercress or Belgian endive. For variation, use boned, skinned, and fat-trimmed chicken thighs (about 1 lb. total) instead of pork; brown the meat (about 6 minutes), then cook with the chutney and water just until the thighs are tender when pierced, 10 to 12 minutes. You may need to add another 1/4 cup water or so to keep the sauce from scorching.